In plasma processing, various elemental and agglomerated powders are melted using a variety of equipment. Particle shape and/or size can be altered by impinging these molten particles against a substrate and causing them to deform or break apart. This can cause the substrate material which is typically in the form of a spinning flat disc to heat to high temperatures approaching or above that of the melted powder. This minimizes the effect of the substrate and also limits the types of substrates that are usable in such high temperature operations.
The present invention provides a disc which is suitable for use in high temperature processing. The disc has multiple layers and is designed to remain relatively cool during the processing.